Takors, R. (Corresponding author)FZJ*

1997
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Report No.: Juel-3420

Abstract: Modeling of microbial growth, substrate consumption and product formation represents an important tool for bioprocess development and optimization. As the determination of kinetic data often requires lots of fermentations lasting several weeks, it is the aim of this work to present an experimental design strategy for an efficient determination of microbial kinetics. Based on closed-Ioop substrate control (nut rist at) an experimental design strategy for the design of steady state experiments is developed. FoIlowing the assumption that a suitable modeling approach is known, a D-optimal design strategy is applied for calculation of steady state operating points. Using this method the identification of macrokinetic model parameters is possible achieving high parameter accuracies. Fermentations were performed with the methylotrophic yeast $\textit{Candida boidinii}$. If an appropriate macrokinetic approach in unknown before kinetic measurements are carried out, it is the task of a discrirninating experimental design to enable model discrirnination within as few experiments as possible. Therefore a model discrirninating design strategy based on entropy formulations has been developed. The analysis of fermentation results as weIl as simulation results demonstrate the quality of this method. To investigate the applicability of steady state kinetic results for the simulation of discontinuous fermentations, batch and fed batch fermentations with $\textit{Candida boidinii}$ were performed. Experimental results are compared to simulation results. An acceptable concurrence between simulations and fermentation results could be stated. Both design strategies as weIl as possibilities for kinetic data analysis and simulation are implemented in the C++ - coded software PARAGLIDE.

1. Institut für Biotechnologie (IBT)